1. Field of the Invention
The present invention relates to multi-channel fiber optic connectors. More particularly, the present invention relates to a new pin configuration for MPO-type connectors, which allows for adjustments and better mating between MPO-type connectors, e.g., to minimize insertion loss between mating channels of mated MPO connectors.
2. Description of the Related Art
Cords and cables with multiple-fiber push-on/pull-off (MPO) connectors are generally known in the art. Such connectors relate to IEC-61754-7 and EIA/TIA 604-5 (FOCIS 5) standards, which are incorporated herein by reference. MPO connectors typically exist in two genders—male with alignment pins or female without alignment pins.
In FIG. 1, reference numeral 11 denotes a male MPO connector, in accordance with the prior art. In initial construction, the male MPO connector 11 has first and second holes 13 and 15 formed in a termination end or front face 17 of a first ferrule 18. First and second alignment pins 19 and 21 reside within the first and second holes 13 and 15, respectively, and protrude away from the front face 17 of the first ferrule 18.
Fiber ends 23 are located in a single row and are aligned between the first and second alignment pins 19 and 21. Although FIG. 1 illustrates eight fiber ends 23 located between the first and second alignment pins 19 and 21, it is known to have twelve fiber ends 23 in a single row, twenty-four fiber ends 23 in two rows, forty-eight fiber ends 23 in four rows, or seventy-two fiber ends 23 in six rows between the first and second alignment pins 19 and 21.
FIG. 2 illustrates a pin clamp 25, which is assembled into the male MPO connector 11. The pin clamp 25 holds the first and second alignment pins 19 and 21, so that the first and second alignment pins 19 and 21 are well anchored within the front face 17 of the first ferrule 18 and not easily removed from the male MPO connector 11 during unmating of the male MPO connector 11 from a female MPO connector or during unmating from a female MPO port.
In FIG. 3, reference numeral 27 denotes a female MPO connector, in accordance with the prior art. The female MPO connector 27 has third and fourth holes 29 and 31 formed in a termination end or front face 33 of a second ferrule 35. The third and fourth holes 29 and 31 are empty and do not possess any alignment pins. Rather, the third and fourth holes 29 and 31 are provided as guidance holes to receive the first and second alignment pins 19 and 21 of a mating male MPO connector 11 or mating male MPO port.
Fiber ends 37 are located in a single row and are aligned between the third and fourth holes 29 and 31. Although FIG. 3 illustrates eight fiber ends 37 located between the third and fourth holes 29 and 31, it is known to have twelve fiber ends 37 in a single row, twenty-four fiber ends 37 in two rows, forty-eight fiber ends 37 in four rows, or seventy-two fiber ends 37 in six rows between the third and fourth holes 29 and 31.
FIG. 4 illustrates a spacer clamp 39, which is assembled into the female MPO connector 27. The spacer clamp 39 has dimensions similar to the pin clamp 25 of FIG. 2. The spacer clamp 39 may assist in manufacturing the female MPO connector 27, such that the female MPO connector 27 may be manufactured using process steps and equipment similar to the process steps and equipment used to manufacture the male MPO connectors 11, except that the step of inserting the first and second alignment pins 19 and 21 is omitted.
FIG. 5 illustrates a genderless MPO connector 41 in accordance with the prior art as depicted in published U.S. Application 2011/0249943, which is herein incorporated by reference. In initial construction, the genderless MPO connector 41 has first and second holes 43 and 45 formed in a termination side or front face 47 of a first, genderless, MPO ferrule 48. The first ferrule 48 is attached to a housing 50. A first alignment pin 49 resides within the second hole 45 and protrudes away from the front face 47 of the first ferrule 48. The first hole 43 remains empty and does not possess any alignment pin. Rather, the first hole 43 is provided as a guidance hole extending into the first ferrule 48 to receive an alignment pin of a mating genderless MPO connector or mating genderless MPO port.
Fiber ends 53 are located in a single row and are aligned between the first hole 43 and the first alignment pin 49. Although FIG. 5 illustrates eight fiber ends 53 located between the first hole 43 and the first alignment pin 49, other configurations are possible. For example, the fiber ends 53 may include twelve fiber ends 53 in a single row, twenty-four fiber ends 53 in two rows, forty-eight fiber ends 53 in four rows, or seventy-two fiber ends 53 in six rows between the first hole 43 and the first alignment pin 49.
FIG. 6 illustrates a pin clamp 55, which is assembled into the genderless MPO connector 41. The pin clamp 55 holds the first alignment pin 49, so that the first alignment pin 49 is well anchored within the front face 47 of the first ferrule 48 and is not easily removed from the genderless MPO connector 41 during unmating of the genderless MPO connector 41 with a genderless MPO connector or during unmating with a genderless MPO port.
The termination side or front face 47 of the first ferrule 48 is the side closest to the mating MPO connector or mating MPO port. The front face 47 presents a generally flat ferrule face. A side of the first ferrule 48 opposite to the front face 47 includes a strain relief boot 52. Fibers 56 exit from the first ferrule 48 on the side opposite to the front face 47 then pass through the strain relief boot 52 before entering into fiber optic cordage 54.
FIG. 7 illustrates a preferred structure for establishing a connection between a first genderless MPO patch cord 81 and a second genderless MPO patch cord 81′. Such a connection may be referred to as a daisy-chain connection between first and second MPO patch cords 81 and 81′. In FIG. 7, the mating of the genderless MPO connectors 41 and 41′ occurs inside of an MPO alignment adapter 59. The MPO alignment adapter 59 provides initial course alignment prior to the entrance of the guide pins 49, 49′ within the guide holes 43, 43′. The MPO alignment adapter 59 also provides environmental, e.g., dust, protection at the mating faces 47, 47′.